Removal of copper, nickel and chromium mixtures from metal plating wastewater by adsorption with modified carbon foam

In this study, the characterizations and adsorption efficiencies for chromium, copper and nickel were evaluated using manufacture-grade Fe₂O₃-carbon foam. SEM, XRD, XRF and BET analyses were performed to determine the characteristics of the material. Various pore sizes (12–420 μm) and iron contents (3.62%) were found on the surface of the Fe₂O₃-carbon foam. Fe₂O₃-carbon foam was found to have excellent adsorption efficiency compared to carbon foam for mixed solutions of cationic and anionic heavy metals. The adsorption capacities for chromium, copper and nickel were 6.7, 3.8 and 6.4 mg/g, respectively, which were obtained using a dual exponential adsorption model. In experiments with varying dosages of the Fe₂O₃ powder, no notable differences were observed in the removal efficiency. In a fixed-bed column test, Fe₂O₃-carbon foam achieved adsorption capacities for chromium, copper and nickel of 33.0, 12.0 and 9.5 mg/g, respectively, after 104 h. Based on these results, Fe₂O₃-carbon foam was observed to be a promising material for treatment of plating wastewater.